Conclusion

The wide habitat range and high dispersal capacity of P. downsi highlights
the significant threat that this parasite poses to the Galápagos
endemic avifauna. Our findings are concordant with the prediction that
parasites with low host specificity [28], good dispersal ability and horizontal transmission will show low population genetic structure and differentiation [56].
Ideally, it is best to eradicate invasive species before they become
adapted to the local environment in which they have colonised and prior
to repeated invasions with the aid of strict quarantine practices [7]. For P. downsi,
this window of opportunity appears to have passed, prompting the need
for a long-term eradication program combined with sustained quarantine
and monitoring practices.